Vehicle airbags are safety devices that deploy toward the interior of a vehicle to help protect its occupants from injury in the event of a crash. Airbags may be concealed behind or beneath an interior panel during normal vehicle operation until such an event. When the airbag deploys, it typically does so through a deployment opening formed in or around the interior panel. The deployment opening may be pre-formed in the panel, the panel may move away to reveal the opening, or the opening may be formed during airbag deployment at a pre-determined location in the panel. Where formed during deployment, a tear seam may be provided in one or more components of the panel to at least partly define the location of the opening, corresponding to an airbag door. The airbag door may open toward the vehicle interior during airbag deployment while remaining attached to the panel by a hinge, tether, or other means so that it is not projected into the vehicle cabin.
U.S. Patent Application Publication No. 2006/0079144 by Klisch et al. describes a plastic substrate for use in a vehicle interior over an airbag. The substrate is molded with a series of elongated recesses along hinge areas of the substrate. A fabric part is included at the hinge areas so that the flaps that swivel about the hinge areas during airbag deployment remain reliably attached with the plastic substrate. The fabric part has a wide mesh configuration and is located in the substrate molding tool during molding so that the molten plastic penetrates the fabric part through the wide mesh and secures the fabric part in place at the back or bottom side of the finished substrate. Tear lines are cut from the back side of the finished substrate with a laser after the molding process. The fabric part is severed and the substrate plastic is partially cut through along the tear lines, and the hinge areas are not laser cut.